Apparatus for releasably interconnecting structural components of rotational symmetry

ABSTRACT

Two structural components are releasably connected to each other by a clamping mechanism which engages two interface rings secured to the respective structural component. The clamping mechanism is formed by tensioning elements ( 5 ) held together by at least one, preferably two straps ( 1, 2 ). A lock ( 15 ) with two hinged tensioning levers ( 18, 19 ) hinged at ( 21 ) to a mounting ( 17 ), holds the strap or straps releasably together. For this purpose each strap end is journalled by a journal bolt to the tensioning lever ( 18, 19 ). Locking elements ( 25, 26, 28, 30 ) hold the tensioning lever ( 18, 19 ) in a locked position in the lock. An electromagnetic drive or the like is used to unlock the tension levers for releasing the tensioning strap or straps in a controlled manner without completely opening the ring formed by the clamping mechanism.

PRIORITY CLAIM

[0001] This application is based on and claims the priority under 35 U.S.C. §119 of German Patent Application 100 33 093.2, filed on Jul. 7, 2000, the entire disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The invention relates to a clamping mechanism for releasably interconnecting structural components having a rotational symmetry such as cylindrical or conical bodies, for example for connecting a payload to a carrier rocket. The clamping mechanism forms a tensioning ring which must be capable of releasing one structural component from the other structural component without completely opening the ring.

BACKGROUND INFORMATION

[0003] Clamping devices that surround the components to be releasably interconnected are known in the art. Hose clamps come to mind. These clamps surround the components in a clamping or tensioning plane. Certain of such devices comprise clamping elements arranged along the radially inwardly facing side or inside of a tensioning strap. The clamping elements have a radially inward facing contour, that cooperates with a respective radially outward facing flange type contour of the structural components to be interconnected. At least one tensioning strap, belt, tape or cable is provided with one eye at each end. A journal bolt passes through the eye and connects the strap end to a clamping element. The other eye is also provided with a journal bolt connected to a respective clamping element. When the clamping elements are operated the two journal bolts move toward each other thereby tensioning the strap around the two components to be releasably interconnected. The clamping elements conventionally separate the strap end completely from each other.

[0004] German patent publication DE 37 27 448 C2 describes a clamping device as described above. Such a clamping device is particularly used in space technology in order to connect a payload to an end stage of a carrier rocket. When the target orbit is reached the payload is separated and released from the carrier rocket by opening the clamping device to thereby completely open the device.

[0005] German patent publication DE-OS 26 55 772 describes another clamping device useful for the above mentioned purposes of separating a payload from a carrier rocket. The clamping device is known as a “Marman” tensioning connector. Just as in the first mentioned conventional clamping device, the “Marman” tensioning connector is also provided with clamping elements on the inner surface of a tensioning belt or strap. The clamping elements are provided on their radially inwardly facing surface with conical recesses which cooperate with correspondingly shaped flanges of interface rings of the structural components to be interconnected. These flanges of the interface rings are secured to the end sections of the structural components to be interconnected. The clamping elements which hold the tensioning strap together are released from the flanges or interface rings or pulled off from these flanges or rings by a pyrotechnically controlled explosion whereby the structural components separate from one another, for example a payload separates from the carrier rocket end stage.

[0006] Even though the explosion is pyrotechnically controlled, it is unavoidable that the sudden separation of the clamping elements suddenly releases a high tension energy that was stored in the tensioning strap. As a result, under certain circumstances it is possible that a relatively strong shock load is applied to neighboring components and systems of the rocket and/or the payload.

OBJECTS OF THE INVENTION

[0007] In view of the foregoing it is the aim of the invention to achieve the following objects singly or in combination:

[0008] to construct a strapping mechanism of the type described above in such a way that the drawback of a sudden tension release is avoided when the strapping mechanism is opened or released;

[0009] to assure that a trouble-free, constant, uniform radially inwardly directed clamping tension is applied along the entire circumference of the structural components to be interconnected;

[0010] to construct the clamping mechanism in such a way that a controlled radial opening motion of the tensioning strap is achieved without completely opening the clamping mechanism;

[0011] to release the tension in the clamping or strapping mechanism gradually and without completely separating the strap ends from each other; and

[0012] to construct the locking mechanism in such a manner that a controlled radially directed opening motion of one or more tensioning straps is assured.

SUMMARY OF THE INVENTION

[0013] The above objects have been achieved according to the invention in that the ends of one or two tensioning straps, belts, tapes or cables are interconnected by at least one locking mechanism that has two spaced and hinged tensioning levers which carry journal bolts passing through eyes at each end of the tensioning strap. Preferably an end of each tensioning lever is hinged to a fixed point, preferably provided by a common mounting. Locking elements are provided on the common mounting for locking the tensioning levers in their tensioning position. Each locking mechanism is provided with two tensioning levers which are tilted toward each other for applying tension to the tensioning strap or straps and which are tilted away from each other to open the clamping mechanism. Several locking mechanisms may be distributed around the circumference of the clamping mechanism.

[0014] When the present clamping mechanism is opened by tilting the tensioning levers away from each other, a clamping ring forming the clamping mechanism is merely enlarged in its diameter without completely separating the ends of the tensioning strap. As a result, opening the present clamping mechanism first transforms the stored energy of the closed status into motion energy and then into elastic energy which is taken up by the strap and not imposed on neighboring components. The length of the opening motion of the tensioning levers can be reduced by distributing several locking mechanisms around the circumference of the circular clamping plane of the structural components, whereby the motion of the clamping elements, especially their radially outwardly directed opening motion, in the tensioning system or clamping mechanism is locally controlled. Sudden jumping of the strap ends is avoided.

DESCRIPTION OF THE DRAWINGS

[0015] In order that the invention may be clearly understood, it will now be described by way of example, with reference to the accompanying drawings, wherein:

[0016]FIG. 1 is a perspective view of the present clamping mechanism in its closed state showing two tensioning straps held together by a single locking mechanism with two tensioning levers pointing toward each other;

[0017]FIG. 2 is a top plan view of an embodiment of the present clamping mechanism in its open state, wherein the two tensioning levers point away from each other;

[0018]FIG. 3 shows a sectional view along section line 3-3 in FIG. 1 whereby clamping elements are shown radially spaced from interface rings of structural components to be releasably interconnected;

[0019]FIG. 4 is a perspective view similar to that of FIG. 1, however on an enlarged scale and showing the locking mechanism in its open state, only the left hand tensioning lever and central locking bar arrangement are shown while the right hand tensioning lever is not shown; and

[0020]FIG. 5 schematically illustrates a force distribution of a clamping mechanism according to the invention and shown in FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EXAMPLE EMBODIMENTS AND OF THE BEST MODE OF THE INVENTION

[0021] The perspective view of FIG. 1 shows the clamping mechanism CM according to the invention as a permanently closed ring that is formed of a plurality of clamping elements 5 circumferentially distributed around the ring shown in a locked condition. The diameter of the permanently closed ring can be reduced for locking and increased for unlocking. The clamping elements 5 are held together in this embodiment by two tensioning straps, tapes, belts or cables 1 and 2 which are spaced from each other in the vertical or axial direction. The axial direction is defined by the central longitudinal system axis of the structural components to be releasably interconnected. The strap 1 has an eye 1′ at one end and an eye 1″ at the other strap end. The strap 2 has an eye 2′ at one end and an eye 2″ at the other strap end. A journal bolt 3 passes through the eyes 1′ and 2′ at one end of the two straps 1 and 2 arranged and parallel to each other. A further journal bolt 4 passes through the respective eyes 1″ and 2″ at the other end of the two straps 1 and 2. These journal bolts 3 and 4 operatively connect the strap ends or eyes to a respective tensioning lever 18 and 19 to form a ring structure as will be described in more detail below. The journal bolts 3 and 4 extend in parallel to each other and in parallel to a ring structure central longitudinal axis which coincides with the system axis. The system axis is also the rotational axis of interface rings 9 and 10 which are conventionally secured to the structural components to be interconnected but not shown in the present drawings. These structural components are of a rotational symmetry particularly they have a cylindrical or conical configuration.

[0022] All of the clamping elements 5 that are facing radially inwardly from the straps 1 and 2 are of identical construction. FIG. 3 shows a section through a clamping element 5 and through the interface rings 9 and 10. Each clamping element 5 has a flat ring surface preferably two flat ring surfaces facing radially outwardly and into contact with the straps 1 and 2. Each clamping element 5 also has an outwardly facing contoured groove G and a radially inwardly facing contour with a clamping channel 6 having preferably slanted conical walls 6′ facing each other across the channel 6. The interface ring 9 has a flange 7 with a conical flange 7′. The interface ring 10 has a flange 8 with a conical surface 8′. These conical surfaces 7′ and 8′ fit into the channel 6 when the straps 1 and 2 are tightened by the tensioning levers 18, 19 of the locking mechanism 15 whereby the two structural components are clamped together. One of the interface rings 9 or 10 is provided with a radially inwardly facing reinforcing ring 11. As shown, the ring 11 is part of the interface ring 10. Assuming the ring 10 is secured to the end stage of the carrier rocket, the ring 11 will provide a stop flange for the insertion of the payload into the ring 9.

[0023] Referring further to FIG. 1, the straps 1 and 2 are held properly spaced from one another in the axial direction by belt clamps 12 having a spring biased arm 13 that engages with its bent free end hook 13′ secured to at least certain of the clamping elements 5. A so-called pull off spring mechanism 14 as part of at least one of the straps 1 or 2, for example strap 1, to facilitate the pull off of the strap from the ring structure.

[0024] Referring to FIGS. 1 and 4 in conjunction, each of the journal bolts 3 and 4 is held in a common locking mechanism 15. The locking mechanism 16 shown in FIG. 2 is of identical construction as the locking mechanism 15. Therefore only one of these mechanisms will be described in detail. Each locking mechanism 15, 16 comprises a common base plate or mounting 17 carrying two hinge blocks 17′ and 17″ as seen in FIG. 1. The mounting 17 has a curvature and radially inwardly contour fitting into the radially outwardly facing groove G formed in the clamping elements 5 shown in FIG. 3, whereby the mounting 17 helps spacing the straps 1 and 2 from each other. The mounting 17 with its hinge blocks 17′, 17″ also fit between the axial end flanges of the interface rings 9, 10. The present locking mechanism comprises two tensioning levers 18 and 19 which are hinged to the hinge blocks 17′ and 17″, respectively. A hinge pin 21 hinges a first end 18′ of the tensioning lever 18 to the hinge block 17′. A second hinge pin 21′ hinges a first end 19′ of the tensioning lever 19 to the hinge block 17″.

[0025] Referring particularly to FIG. 4, both eyes 1′ and 2′ of the straps 1 and 2 are journaled to the clamping lever 18 by the same journal bolt 3. Referring to FIG. 1, the eyes 1″ and 2″ are journaled to the tensioning lever 19 by the same journal bolt 4.

[0026] The tensioning levers 18 and 19 are preferably constructed as so called quick action tensioning levers. Only the tensioning lever 18 will be described in detail. The tensioning lever 19 is of a same mirror symmetrical construction relative to the lever 18. Each clamping lever 18, 19 includes a rectangular frame 20 hinged by the hinge pins 21, 21′ to the hinge blocks 17′, 17″ as mentioned above. The journal bolts 3 and 4 extend in parallel to the hinge pins 21 and 21′. The bolts 3, 4 and pins 21, 21′ extend in parallel to the central system axis.

[0027] The opposite end of each tensioning lever 18, 19 is provided with a threading in which a tensioning screw 22 is received. An unthreaded end of the tensioning screw 22 extends out of the frame 20 but the threading is of sufficient length to accommodate a counter nut 22′ which locks the tension adjustment screw 22 relative to the frame 20 in an adjusted position. The inner end of the tension screw 22 is rotatably secured to a guide block 23 for adjusting the guide block 23 lengthwise within the frame 20 of the tensioning lever 18. The frame 20 has in its upwardly and downwardly facing frame sections elongated holes 24 through which the journal bolt 3 extends into and through the guide block 23. Thus, the ends of the journal bolt 3, 4 stick out upwardly and downwardly of the frame 20 into the respective eyes 1′ and 2′, and 1″ and 2″, respectively. The outer end of the frame 20 carries a locking bail 25 the function of which will be described below. When the counter nut 22′ is loosened the position of the guide block 23 shown in FIG. 4 can be adjusted within the frame 20 to tension the straps 1 and 2 since the journal pins 3, 4 pass the guide block 23 and are enabled to move back and forth along the elongated guide holes 24 with the guide block 23.

[0028] As best seen in FIG. 4, the locking bail 25 is constructed for cooperating with a locking bar 26. The locking bar is slidably mounted in a support 27 secured to the base plate or mounting 17. The sliding motion of the locking bar 26 extends in the direction circumferentially around the clamping mechanism. This applies also to the locking bar 30 which cooperates with a respective bail of the tensioning lever 19 not shown in FIG. 4. Both ends of each locking bar 26 and 30 extend out of their respective supports 27 and 29 which are secured to the mounting 17. The locking bar 26 has a ramp shaped end surface 26′. Similarly the locking bar 30 has a ramp shaped end surface 30′. While the lever facing end of the locking bar 26 engages the bail 25 the opposite ramp shaped end 26′ cooperates with a slanting surface of a wedge unlocking-locking element 28. The ramp surface 30′ of the other locking bar 30 cooperates with the same wedge element 28. The wedge element 28 is movable up and down as indicated by the arrow 28′ guided by a guide bar 31 that extends in parallel to the central longitudinal axis of the clamping structure. The construction of the locking levers 18 and 19 is mirror-symmetrical relative to a plane passing longitudinally through the guide bar 31 of the wedge 28.

[0029] In its open state with the tensioning levers in the position pointing away from each other as shown in FIG. 2, the present clamping mechanism fits over the flanges 7, 8 of the ring sections 9, 10 without the need for completely separating the ends of the straps 1 and 2. By simply tilting the lever 18 in the clockwise direction CD as shown in FIG. 4 and the lever 19 counterclockwise the clamping mechanism is tensioned to bring it from the position shown in FIG. 4 to the position shown in FIG. 1 wherein a circumferentially effective tensioning or clamping force is applied to the straps 1 and 2. The radially inward displacement of the clamping elements 5 is caused by the tensioning levers 18 and 19 through the straps 1 and 2, whereby the tensioning adjustment is substantially reduced in its length by means of the threaded screws 22. When both levers 18 and 19 are in the position pointing toward each other as shown in FIG. 1 the final tensioning is complete. The tensioning screws 22 are turned when the levers 18, 19 are in the open position and when the counter nut 22′ is loose to bring the guide block 23 and thus the journal bolt 3, 4 into the proper position. In the final position the counter nut 22 is tightened again.

[0030] When the tensioning levers 18 and 19 are in the position shown in FIG. 1 pointing toward each other the bail 25 is engaged by the hook end of the locking bar 26 and the respective bail of the clamping lever 19 is engaged by the hook of the locking bar 30 to keep the tensioning levers 18 and 19 in the locked position.

[0031]FIG. 5 illustrates in a force diagram the forces that are effective on the clamping lever 18. The tensioning forces F3 and F4 are introduced into the straps 1 and 2 through the journal bolt 3. Due to the diameter of the journal bolt 3 an angle α exists between the tensioning forces F3 and F4. This relatively small angle provides the force component F5 which constitutes a holding force when the clamping mechanism is in its closed condition. An unintended opening against the force F5 is prevented according to the invention by a mechanical safety device in the form of the above mentioned wedge 28 in its upper position along the guide rail 31. When the clamping mechanism is to be opened intentionally, the wedge 28 is forced downwardly thereby moving the locking bars 26 and 30 slightly away from each other for disengagement from the respective locking bails 25. The movement of the wedge 28 downwardly in the opening direction is for example accomplished by an electro magnetic drive not shown. However other drives for moving the wedge 28 downwardly may be employed.

[0032] The ramp shaped end surface 26′ of the locking bar 26 and the ramp shaped end surface 30′ of the locking bar 30 cause a controlled opening of the system in a timed relationship so that a slow opening and a respectively delayed release of the tensioning energy is assured. This controlled, timed release of the tensioning energy of the straps 1, 2 is additionally enhanced by the direction of the force F5 which according to FIG. 5 becomes larger when the angle a becomes larger thereby providing the resulting opening force in the opened system. Simultaneously there is friction in the entire system that friction in combination with the mass inertia forces of the tensioning and locking components and of the tensioning straps supports the controlled timed sequence of the opening or tension release operation, whereby the straps 1, 2 cannot jump in an uncontrolled manner. The clamping mechanism according to the invention as described above provides a simplified construction with more functions than are conventionally available. The opening of the mechanism is accomplished by moving the tensioning lever 18 counterclockwise and the tensioning lever 19 clockwise whereby the clamping elements 5 merely move slightly apart and the entire system including the tensioning levers 18 and 19, the mounting 17 and the straps 1 and 2 still remain as a “closed” ring even in the open state. During the opening motions the tension energy stored in the system is first converted into a motion energy and then again into an elastic energy of the straps. The strap holders 12, 13 and the pull off spring mechanism 14 serve during the opening or rather during the enlargement of the diameter of the ring for locally limiting the motion of the elements forming the ring so that a controlled radial motion component of the clamping elements 5 is supported and the entire tensioning ring system is locally fixed.

[0033] The straps 1 and 2 described above for the example embodiment may be replaced by tapes, belts or cables. Any of these tensioning elements optimize the surface pressure of the contact surface area between the clamping elements 5 and the interface rings 9 and 10. More specifically a uniform pressure distribution is achieved around the entire circumference of the cooperating ring surfaces. Such a uniform pressure distribution results in a uniform radial load distribution through the clamping elements 5 onto the contact surface 7′ and 8′ due to the uniform contacting around the entire circumference of the just mentioned surfaces. The spacing, if any, between neighboring clamping elements 5 in the circumferential direction is uniform all around the interface rings 9, 10.

[0034] By selecting the proper length of the tensioning straps 1 and 2 and by arranging the required number of clamping elements 5 and locking mechanisms 15, 16 it is possible according to the invention to construct the present clamping mechanism for practically any required diameter of the interface rings 9 and 10 or their flanges 7 and 8. Even structural components with very large diameters can be safely and releasably interconnected by the present clamping mechanism thereby avoiding the conventional problem that conventional clamping mechanisms could not accommodate very large diameter components. Heretofore it was necessary to use more complicated and particularly heavier connection mechanisms. According to the invention a further advantage is achieved in that the calculations of the required strength values of the present clamping system do not need to take into account any bending moments at the interface rings 8 an 9 because such bending moments are avoided. The present clamping elements 5 with their channel 6 uniformly engage the slanted clamping surfaces 7′, 8′ of the interface rings 9 and 10. This engagement of the flanges 7 and 8 in the groove 6 of the clamping elements 5 results in a system having a high load carrying capability whereby this capability is substantially limited only by the material strength of the interface rings 9 and 10 specifically their flanges 7 and 8.

[0035] As mentioned above it is possible to use but one locking mechanism 15 or 16 around the circumference. However, for larger diameter structural components several such locking mechanisms 15 and 16 may be distributed around the circumference of the respective interface rings.

[0036] Although the invention has been described with reference to specific example embodiments, it will be appreciated that it is intended to cover all modifications and equivalents within the scope of the appended claims. It should also be understood that the present disclosure includes all possible combinations of any individual features recited in any of the appended claims.i8 

What is claimed is:
 1. An apparatus for releasably interconnecting two structural components (9,10) having radially outwardly reaching clamping surfaces (7′,8′) of rotational symmetry, said apparatus comprising a plurality of clamping elements (5), at least one tensioning strap (1 or 2) holding said clamping elements (5) together, said clamping elements (5) comprising a radially inwardly facing clamping groove (6) adapted for cooperation with said clamping surfaces (7′,8′) of said structural components, said at least one tensioning strap comprising two connecting eyes (1′, 2′), whereby one eye is secured to each strap end, journal bolts (3, 4) one of which passes through each of said eyes (1′, 2′), at least one locking mechanism (15) interconnecting said journal bolts (3, 4) for moving said journal bolts closer to each other in a clamping operation, said at least one locking mechanism (15) comprising two tensioning levers (18, 19), two hinges with hinge pins (21) securing said tensioning levers (18, 19) to a respective fixed point, said journal bolts (3, 4) connecting said strap ends to a respective tensioning lever (18, 19) of said two tensioning levers (18,19), and locking elements (25,26,28,30) for locking said tensioning levers (18,19) in a strap tensioning position.
 2. The apparatus of claim 1, further comprising a mounting (17) forming two hinge supports (17′, 17″) for each said fixed point of said hinges of each of said tensioning levers (18,19), said mounting (17) having a radially inwardly facing first contour matching a radially outwardly facing second contour (G) of said clamping elements (5), said first contour of said mounting (17) having a curvature with a diameter corresponding to a curvature diameter of said second contour (G).
 3. The apparatus of claim 1, wherein said tensioning levers (18, 19) of said at least one locking mechanism (15) together form a quick action tensioning mechanism.
 4. The apparatus of claim 1, wherein each of said two tensioning levers (18, 19) comprises one of said locking elements formed as a locking bail (25), and wherein said locking elements further comprise two locking bars (26, 30), one locking bar cooperating with each locking bail (25), and two supports (27,29) each slidably holding a respective locking bar (26 or 30) of said two locking bars (26,30).
 5. The apparatus of claim 4, further comprising a mounting (17), said locking elements further comprising an unlocking wedge (28) positioned on said mounting (17) between said two supports (27, 29) secured to said mounting (17), a guide rail (31) on said mounting (17) guiding a sliding motion of said locking wedge (28) relative to said locking bars (26, 30), and wherein each of said locking bars (26,30) has a ramp shaped end surface (26′,30′) for cooperation with a respective slanting surface of said unlocking wedge (28).
 6. The apparatus of claim 1, comprising a plurality of said locking mechanisms (15, 16) distributed circumferentially around said clamping surfaces (7′,8′).
 7. The apparatus of claim 1, comprising at least two tensioning straps (1,2) arranged in parallel to each other, each of said straps comprising an eye (1′, 2′, 1″, 2″) at each of its ends, and wherein each of said journal bolts (3, 4) passes through two eyes (1′, 2′) of said two tensioning straps (1, 2).
 8. The apparatus of claim 7, wherein said at least two tensioning straps (1, 2) define a clamping plane of rotational symmetry around said structural components (9, 10) said clamping plane having a diameter determined by said structural components, and wherein said hinge pins (21) have a hinging axis extending in said clamping plane.
 9. The apparatus of claim 7, wherein said at least one locking mechanism (15) interconnects said tensioning straps (1,2) in such a way that a circumferentially closed unit is formed of said tensioning straps and of said at least one locking mechanism (15) when said at least one locking mechanism is locked and unlocked.
 10. The apparatus of claim 1, comprising a mounting (17) forming said respective fixed point for each of said two hinges, wherein each of said tensioning levers (18,19) comprises a first lever end (18′,19′) forming a hinge end hinged to one of said tow hinges by said hinge pins (21), a second lever end opposite said first lever end (18′) said locking elements including a locking bail (25) secured to said second lever end, an opening (24) in said lever (18, 19) between said lever ends, and wherein each said journal bolt (3, 4) is operatively held in a respective opening (24) between said lever ends for tightening said tensioning strap when said lever is tilted about said hinge pin (21) in a tightening direction.
 11. The apparatus of claim 1, wherein each of said tensioning levers (18, 19) comprises a lever frame (20) comprising frame sections interconnecting first and second lever ends, said frame sections forming an opening (24) as a guide channel between said lever ends in said lever frame (20), said guide channel (24) guiding said journal bolt (3).
 12. The apparatus of claim 11, comprising two tensioning straps (1, 2) spaced from each other, wherein said lever frame (20) is positioned between said spaced straps, said apparatus further comprising a guide block (23) slidably received in said guide channel, and wherein said journal bolt (3) connects both tensioning straps through their eyes and through said guide block (23), whereby said journal bolt (3) is movable with said guide block relative to said lever frame (20).
 13. The apparatus of claim 12, further comprising a threaded tensioning screw (22) passing through a threaded hole in said second lever end into said guide channel, said tensioning screw having an inner end rotatably connected to said guide block (23) for shifting said guide block (23) and with said guide block (23) said journal bolt (3) along said guide channel in said lever frame (20).
 14. The apparatus of claim 13, further comprising a counter nut (22′) on said tensioning screw, said counter nut bearing against said lever frame (20) when said counter nut is tightened to hold said tensioning screw in an adjusted position.
 15. The apparatus of claim 12, wherein said mounting (17), comprising a hinge block (17′), said hinge pin (21) connecting said first lever end (18′) to said hinge block (17′) for tilting movement of said lever (18). 